When brothers agree, no fortress is so strong as their common life.
—Antisthenes, Greek philosopher

ON A CHILLY AUTUMN morning in Washington, DC, with the sun still catching its last bit of sleep, the Lea family clusters around the youngest, Syd, 26, getting him ready for a 110-kilometer ride they will take together at the Audi Best Buddies Challenge, an event that pairs mainstream and intellectually challenged riders.

"Baah-BEE, last year I was COLD," Syd protests to his brother, who is encouraging him to remove a layer of clothing on what promises to become a fine morning.

Bobby Lea, 28, smiles indulgently. "It was bad weather last year, Syd," he says. "This will be different." Bobby nods toward his mother, who is also fussing over Syd. "Mom hates to be cold, too," Bobby says. "She's dressed for five hours at 35 below."

On countless mornings, in countless events and competitions, in countless venues in countless countries, the Leas have nested exactly like this. Rob, the father; Tracy, the mother; and the two boys, Bobby and Syd, bundling, gathering, stretching, testing, zipping, unzipping, strategizing, chattering away the nerves and the morning chill. The Leas are arguably, right now at least, America's First Family of Cycling, with an Olympian (Bobby), an elite masters male rider (Rob), a competitive masters female rider (Tracy), and a rider who blows away most of the world's competition in both Special Olympics and a division for the intellectually impaired (Syd).

Syd is a muscular, strapping young man, 6-foot-2, 195 pounds, his nickname of "The Bus" coming from the brute power he demonstrates when he's on the bike. He's dark and striking, and a sly smile often plays around his lips. At Mount St. Mary's University in northern Maryland, where he works on the grounds crew, it is not unusual for coeds to flirt with him. Syd likes the attention but doesn't quite know what to do about it.

His not-unusual appearance is at once a great blessing and a curse. Syd walks through life as most of us do, and it is only when a stranger engages him in conversation that he turns out to be a little different, the result of a cyanotic episode that occurred in the hospital nursery, a couple of medically inexplicable minutes on his second day of life that came to define him. He is unlike most of the other young men and women against whom he usually competes. Not much is expected from them; much is expected from Syd.

On an entirely different plane, of course, more is expected from Bobby. He has qualified for the long team from which will come the final selections for this year's Olympic Games, which would be his second appearance, following Beijing in 2008. He will, presumably, carry on his shoulders America's hopes in the omnium, a six-event velodrome competition that will be contested over two grueling days in London. Both are slender—his shoulders and his chances at medaling. "It [getting a medal] would be more of a dream outcome than a tangible goal," says Bobby. That sentiment seems reflected in his pre-Olympic season that has seen ups (seventh in a World Cup event in Beijing, and first in the scratch race and individual pursuit at the Pan-Am Games) and downs (16th and never competitive in another World Cup event in London).

The sun rises, the crowd swells, and the Leas make their way to the start. More of the participants recognize Syd, who won three gold medals in the 2011 Special Olympics World Summer Games in Athens, than they do Bobby, who has won more than 50 national titles as an amateur, collegian, then pro. This is Syd's crowd. A banner encourages everyone to spread the word to end "the word," part of the Special Olympics crusade to stamp out "retarded."

When the gun sounds, the pack takes off and about three-and-a-half hours later, rounding the turn onto the National Mall, comes a pack of Leas, all but Tracy, who had never intended to pedal all the way. As they near the finish, Bobby and his father slow down and Syd crosses the line first, arms raised in triumph. This is only partly a setup. Yes, Bobby could've crushed his brother, but Syd could've crushed Rob, who, though still a formidable competitor in his age group—he won a criterium just last year—is, after all, 70. Syd's ride would've put him in the middle of the pack in many Category 3 races in many cities on many Saturday mornings.

"I BURNED you!" Syd says to another rider, an adult, who crosses a couple of minutes after Syd. He doesn't say it challengingly. It's just a statement of fact.

"One of the great things about being Syd," says his mother, "is that he can say all those things we all want to say." Although sometimes he says things you don't want to say. After losing a close race once, he proclaimed, "I got nibbled at the finish line."

SYD LIVES WITH TRACEY and Rob in the small Carroll County town of Harney, post-office address of Taneytown, Maryland. The hedgerow on their 17-acre property sits just on the south side of the Mason-Dixon Line. It's not a working farm, the animal population comprised of a border collie named Trudie and two miniature donkeys, Smudge and Radar, whom Tracy refers to as "grass-eating lawn ornaments."

A barn sits near their spacious farmhouse, though that label hardly does it justice. The red building houses an equipment room with enough bikes, tubes, tools, and pumps to outfit a small team; a wonderful workout gym that includes free weights, a stationary bike, a Concept 2 rowing machine, and a variety of biking memorabilia that would make a museum curator drool; and a fully appointed apartment with a bedroom suite. Syd has slept out there a few times, testing his independence, but always he returns to the main house, feeling more comfortable in his own room, amid his medals and mementoes, just off the living room with the wood stove that so cozily heats the Lea home.

Syd has friends among his fellow workers at Mount St. Mary's, with whom he can jawbone about his primary passion—football. (Several years ago, his favorite player, Tom Brady, threw him a pass at a Best Buddies event.) Beyond that, he has best buds all around the world, knows officials, chats with sponsors, catches up with fellow competitors. "Unlimited calling was a major development for Syd," says his mother. If one of them invites Syd for a visit, he takes it quite literally; he will immediately begin planning for the trip then make it happen, even if that means hopping on a plane to, say, Finland.

But, now, at his age, there must be times when Syd Lea takes a survey and sees a paired-off world—mother with father, brother with girlfriend, coworkers with wives—and wonders if there will ever be someone just for him.

BOBBY HAS SPENT MUCH time alone, too. As he was entering his teen years, already a recognized rider on the national circuit, circumstances became untenable at the Lea home in Easton, Maryland, on the eastern shore of Chesapeake Bay. A relative outside of the nuclear family had begun assaulting him—it was not sexual—"the culmination," Bobby says, "of two years of slowly escalating crap." Rob and Tracy wanted Bobby away from the trouble as soon as possible, and, after a frenetic search and a few dozen phone calls, Tracy found a place, a converted one-room schoolhouse in Topton, Pennsylvania, a small town of about 2,000 in eastern Pennsylvania. It was near a frame-building cousin (Tom Kellogg) who could keep an eye on him, a circle of cycling friends of Rob and Tracy ("I could keep tabs on what was going on in the sandbox," she says) and, fortuitously, the Lehigh Valley Velodrome, one of the finest facilities in the country.

The velodrome was already familiar to Bobby, who had competed there many times. Jack Simes III—a three-time Olympian, the former director of the velodrome and the father of Jackie Simes IV, who sometimes partners with Bobby in two-person Madison races, in which riders sling each other into the fray at speed—remembers Rob and Tracy settling three-year-old Bobby onto a two-wheeler on the backstretch, his first go without training wheels.

At the time of the family upheaval, in the spring of 1999, Bobby was an indifferent student at Gunston Day High School in Centreville, Maryland. "A seventh-grade homeroom teacher called me a 'coaster,' and I guess that was accurate," he says. His mom devised a plan, outrageous in retrospect, in which Bobby would earn his GED and enroll as a 15-year-old at the Lehigh Valley campus of Penn State University, which had an outstanding cycling team. Tracy, who had twisted more than a few arms to get educational and competitive opportunities for Syd, was even successful at getting the school to admit Bobby provisionally before he passed the GED. He became a 15-year-old collegian, gaining official acceptance when he passed the test at 16. "I'd like to call it a grand achievement," says Bobby, "but a sixth-grader with honors math could've done it."

Predictably, there was skepticism when his coach inserted what amounted to a high-school sophomore into their race-day plans. "A few were, I'd venture to say, appalled that I was using someone that young," says Jim Young, then, as now, the coach at Penn State. "That opinion changed pretty fast." Bobby won National Collegiate Cycling Association (NCCA) titles in the individual pursuit and the individual omnium in his freshman year, making him, as far as most sources can verify, the youngest person to win a collegiate championship in any sport. Before he was done at Penn State in 2006—being a coaster, he did take six years to get his degree—Bobby had dominated collegiate cycling like no one before or since.

He has not translated that level of success into his pro career. "I've never been on the world stage at any one thing," says Bobby. "I've always been a kind of jack-of-all-trades. The omnium is a chance for someone like me, someone who can do all the events maybe 1 percent lower than the top specialists, and do them all back-to-back."

More on that later, but, at this point, Bobby would surprise a lot of people if he gets near a medal in the Olympics. Including, most tellingly, himself.

SEVERAL MONTHS AFTER BOBBY left for Topton, the family relocated to its farm outside of Taneytown, which made Syd, who was beginning his freshman year, a stranger in a strange land. Syd was months into the school year at Francis Scott Key High when his parents discovered that their youngest, caught between the worlds of the mainstream and the intellectually challenged, would go days without talking to anyone.

So Tracy put on her lobbyist's hat, making sure that Syd got extra help and varying his academic schedule between regular-track and vo-tech classes such as landscaping. He graduated in 2004, but, as he looks back now, Syd, ever candid, says: "Francis Scott Key. I didn't like it there."

Syd has other passions, particularly if there's pageantry involved. He has been to Broadway musicals, and likes to listen to Handel's Messiah and opera performances. To Syd, there is no façade to performance; it is reality writ large.

But most of all there has been sport, beginning with equestrian. The four-year-old Syd was almost mute, and when he spoke at all it was in a whisper. Research shows that communication skills and impulse controls of the intellectually challenged can improve through interaction with animals, so Tracy, who had a background in equestrian, started Syd in therapeutic riding classes. Soon he was competing in Special Olympics dressage—and telling people all about it, and everything else. The quiet version of Syd is hard to imagine, given the riot of words that tumbles out of him now, as they did in the days before the NFL conference championship games: "TomBrady TomBrady will not lose the Ravens can't stop can't stop Brady but the 49ers will beat the Giants, and if they get a big lead early I'll go to bed because I have to work the next day..."

Not surprisingly, cycling became Syd's best sport, and he began to dominate the local Special Olympics competition, then the national, then the international, culminating with his road-race gold sweep in Athens. (Syd's victories came in the 15-kilometer at 23:25.79, the 25-kilometer at 40:32.34, and the 40-kilometer at 1:10:33.00.) Even at the highest level of Special Olympics competition, Syd often goes up against athletes with physical handicaps (he has none), and there is almost no one close to his physical ability. He finds more competition in INAS (Athletes with an Intellectual Disability), but even there he won gold in both individual events (road race and individual time trial) at the 2011 INAS Global World Games in Italy.

Thinking about his serious INAS competition—four similarly fit young men from Portugal, Germany, the Czech Republic, and Australia—moves him to train, even in bad weather, even if there's a football game on the tube. "There's riders who can beat me, but not if I'm at my best," says Syd. He's just being honest.

IS THERE AN OLYMPIC gene? Something passed along from parents to son, something in the code that predetermines a willingness to endure pain, push a little harder, pursue a dream that so few can attain?

Rob Lea was 5-foot-9 and 170 pounds when he made the 1964 United States Olympic rowing team as an alternate. Most outsiders who had seen him carrying an oar to practice at Harvard figured he was the coxswain. He got into weight and interval training before it was popular, rowed a double at the Henley Regatta, studied up on the world-class teams, won a gold medal in doubles at the 1963 Pan-Am Games in São Paulo, and combined all that with an indomitable work ethic and an astonishing aerobic capacity that put his resting pulse in the mid 30s. A normal strokes-per-minute rate is 28 to 32; Rob rowed 38 to 40 when he was alone in a boat. His sweat got him to Tokyo, and he is one of the smallest Olympic rowers ever, someone comparable to, say, a 5-foot-3 point guard.

He wasn't medal potential, though, and a teammate (the late Sy Cromwell, one of the greatest American rowers) suggested he take up cycling. He was the ideal size and his ability to train and recover was off the charts, so cycling became his new passion as he pursued his doctorate in education at Harvard. He met a youth worker and avid cyclist named Tracy DeNagy at a time trial, and they were married in 1977, a few days after competing in a race in Arkansas.

Rob and Tracy went everywhere with their bikes, and, after Bobby and Syd came along, their kids went with them. Bobby was less than two years old and Syd only two months the first time they went to Austria. (The brothers have a friendly competition about who's been in more countries, though Bobby says Syd is a bit of a cheater. "If Syd connects at an airport, he counts it," says Bobby with a smile. "I tell him that you have to get out and actually do something.")

The parents still rarely miss an opportunity to compete. As Tracy showed a visitor around her house not long ago, she explained a blackened right eye as a souvenir from the 2012 UCI Masters Cyclocross World Championships, in Lexington, Kentucky. "I hit a barricade," she said, shrugging. Rob has won eight national masters championships on the track and the cyclocross nationals twice. Internationally, he won the points race in the World Masters Games in Denmark in 1989 and has a second in the World Masters Road Race in Austria in 1983, all while helping to raise two sons and run a full-time psychology practice. "I'm pretty sure," Rob says, not without reason, "that I could've been an Olympic cyclist if I had started earlier."

And so the broad strokes of this family athletic dynamic seem drawn. The athletic, resourceful mother, protective but determined to push her boys into challenging circumstances. And the undersized, driven, Napoleonic father, the classic overachiever, one of two Olympians in the family (the other is Charlie Kellogg, who competed as a cross-country skier at the '68 Winter Games in Grenoble, France), the warrior who would crow about his world-class aerobic capacity, and, in the manner of the Great Santini, browbeat his sons into training.

Except it didn't happen that way. Indeed, Bobby remembers being surprised when he learned, around age 12 or 13, that his father had been an Olympian. "He never mentioned it," says Bobby, "but that's just how my dad is."

His mom and dad put him on the bike and Bobby loved it, coercion unnecessary. One of his earliest memories is competing as a four-year-old and getting nipped (Syd might say "nibbled") because he slowed down in the backstretch. "I thought you had to stop right on the finish line," he says. Bobby won his first national title in 1997 when he was 13 and started racking up those college titles a few years after that. He grew tall—he's 6-foot-2 now, the same as Syd—and strong, though at 170 he's not particularly muscular. He's built just a little too big to fit into the traditional road racer's mold, but is ideal for endurance track events—which he wryly refers to as "the red-haired stepchild of U.S. Cycling."

For 12 years now, Bobby has trained near his Pennsylvania home, where he can set out in almost any direction and pedal long, unpopulated stretches of rural road into an array of small towns, the quaintness cup running over. Sally Ann Furnace Road. Huffs Church. Dryville. Fleetwood. Virginville. One of his favorite midride stops is Wanamaker's General Store—which is exactly what its name says rather than a tourist attraction with a charming façade. And when he rides into "downtown" Topton, he might be able to cadge a PBR at the White Palm Tavern, which hands out a free beer when a train whizzing by on the nearby tracks sounds its whistle.

The converted schoolhouse (complete with tower bell) in a place called Topton sounds like the quintessential domestic setup for a quiet cyclist who left home when he was 15 and trains mostly alone, sometimes setting off on jaunts as long as six hours. But Lea's life isn't monastic. A decade ago he met a high school senior named Erin Vavra when he volunteered to visit a class to give a bike-safety course. It took a while for Bobby to make the right move ("I had no game," he says), but they now live together. "I'm a first-grade teacher living in a schoolhouse," says Erin. "Sometimes I can't believe that myself."

THE JANUARY WIND BLOWS cold and unceasingly across the campus of Mount St. Mary's in Emmitsburg, Maryland, about 15 miles south of Gettysburg, Pennsylvania. Syd, who works two or three days a week, is out in the middle of it, digging trenches. His shift is over at 3.

"Tell you the truth, I'd like to have Syd here more," says his boss, Elvin Wolfe, the Mount St. Mary's grounds manager. "He's a great worker." When Syd started five years ago Wolfe put him with a job coach, but it wasn't long before Syd could handle the small tasks alone. Then the big tasks. Now, in the summer, Syd himself leads a small crew of interns and high-school kids.

"Sure, there are limitations," says Wolfe. "He doesn't always know the names of plants, for example. But there are limitations with every worker. And certain things, like weed whacking, Syd does better than anyone."

It is time for Syd to drive home, which conjures up the most colorful part of Syd lore—his Sisyphean struggle to get a driver's license. The story goes that Syd passed the on-road test on the first shot—though there is some dispute about that in the family record—but everyone agrees he needed what might be a state record of 25 passes at the written portion. After he finally made the mark, a state trooper put his arm on Syd's shoulder and said, "Well, Mr. Lea, we were about to put a nameplate for you on that chair."

Syd is ultra-careful behind the wheel of his 1994 VW Jetta bearing a sticker that reads SYD'S CAR. He is a fanatic for turn signals, staying under the speed limit and remaining on the correct side of the yellow line, just like in a bike race; if another driver violates that provision, Syd will enter the house and start fuming about "the guy who crossed the yellow line."

Syd may be like a child in some respects, but he is a fully grown man, sometimes stubborn and willful, his rituals sacrosanct, literalness his default mindset. (On one occasion after a race, Tracy told him that he had lost his voice, and Syd said, "We have to go back and look for it.") He removes his work boots, tucking the laces carefully inside with the same care that an altar boy takes to deliver the communion wine. He likes to decompress when he comes home, catch some sports news on ESPN or maybe peruse his Football Book, in which he carefully enters the NFL scores of the week. (All of the teams are spelled correctly except for the Jets, who are the "Jest," a delightfully accidental truth.) And he would gladly engage you in a conversation about Tim Tebow's private life.

"He, he, doesn't have any girlfriends," Syd says.

"I wouldn't be sure about that," a visitor answers.

"NO!" insists Syd. "No girlfriends!"

On this day there is a guest who must watch him work out on his rowing machine, and Tracy tries to move him along. He is not having it and goes at his own pace. Once in the gym, she asks him to row against the machine's avatar, the Pace Man.

"NO-OOOO!" Syd wails. "MOM! NO! I don't want to!" Tracy tries to ignore the shouts of protest and adjusts the machine to pair up Syd with the avatar. Syd's intransigence is based on two factors: This was not on his training schedule and he is a creature of routine, and, second, in the past he has fared poorly against Pace Man and Syd Lea HATES to lose.

He is still screaming "NO-OOO" when Tracy, no slouch in the stubbornness department herself, sets the machine and tells him to get ready. Syd blows out a heavy breath, steels himself, and begins a furious stroking sequence that blows away Pace Man.

The latest thinking in the Lea household is that Syd's best sport might be rowing. Over the winter of 2012 he shattered most indoor world rowing records for the intellectually impaired. Not surprisingly, if you know the family dynamic by now, it was Tracy, not Olympic rower Rob, who coaxed Syd into the boat, entering him in a Paralympics event. "I was skeptical, but Tracy pushed and pushed," remembers Rob, "and, gradually, I became convinced that he could do this. I mean, what a body for rowing this guy has, and he's got the mentality for it, too. That means coming to race day and being able to go all out instead of being scared. Syd rowing 35 strokes a minute with all that strength? In singles?"

Rob leaves the question in the air. Could Syd be a successful mainstream rower? "Well, no, not that good but..." He reconsiders. "Heck I don't know. He's already progressed so much further than anyone thought he would."

WHEN TRACY AND ROB brought Charles Sydney Lea home from Maryland's Easton Memorial Hospital in June 1985, they knew about the occurrence of the cyanotic episode, but no one was sure how long Syd had turned blue because of oxygen deprivation (one minute? two minutes?), and he seemed healthy. But the Leas already had a son for comparison, and gradually it became clear Syd was different. "As I look back," says Tracy, "the hardest part was when I was handed his official diagnosis. Syd was two, and the pediatrician says, 'He flunked.'"

Tracy doesn't cry much, being one who prefers to do rather than reflect. But now she dabs at her eyes. "Imagine hearing that your two-year-old flunked," she says. "That hits you. That hits you hard. As a parent you have aspirations of what your child will be able to do, and now you're hearing that those won't happen."

Bobby doesn't remember an a-ha moment when he learned that Syd was different. "What I remember was that Syd would get more slack for behavior issues than I would," says Bobby. "That made the biggest impact on me, and gradually I came to understand why."

Bobby is asked if his personality—quiet, thoughtful, analytical—was formed in part by being the brother of a demonstrative special-needs kid. "Not at all," Bobby says. "You have to remember that the Syd you see now is not the Syd I grew up with. That Syd was kind of muted, and it's been interesting over the last few years to watch him grow into his own person, create an identity outside of being my younger brother or my parents' son. In the process he's created this larger-than-life personality."

Despite Syd's limitations, and Bobby's longevity as a top rider, their relationship often carries this question as paradoxical subtext: Bobby, if you were more like Syd, how much better would you be? Syd is the character of the two, so outgoing and full of life, so strong and seemingly implacable, that he seems more the warrior. When Syd gushes over a cyclist, it is usually British road specialist Mark Cavendish, an electrifying sprinter with a gung-ho personality.

That doesn't describe his brother. "Bobby is always even, always measured," says Doug Eldridge, who manages Bobby out of the Washington, DC-based DLE Agency. That jibes with Bobby's racing style, which is cerebral. He was able to beat riders five and 10 years his elder when he was a teenager largely because he mastered the subtleties of cycling, when to ride a wheel, when to hang back, how to best muster his energy reserves.

But despite all that Bobby has accomplished, and all knowledge and potential, he hasn't broken into the top of his sport. He isn't signed on with an international team, let alone one of the best-in-the-sport ProTour teams that could get him into competitions such as the Tour de France. Says Mike Friedman, who rode with Bobby in Beijing and, briefly, raced at the ProTour level, gaining experience in famed events such as Paris-Roubaix, "Dude, if I knew why Bobby hasn't been signed by a top team or why he never seemed to reach his potential, I would have an answer to one of the great mysteries." Even Bobby searches for an explanation. "I do have a strong sense that I haven't performed to the best of my ability," he says. "I know my career seems unfulfilled."

One theory he'll voice is that the select invitations haven't come along because he is an Olympics-oriented rider in a sport that caters to top roadies. "My reputation as a track rider has probably pigeonholed me," he says. "What I am hoping to do is capitalize on this second Olympics to push through that track barrier." If that's the case, a more gung-ho prognosis than "[medaling] would be more of a dream outcome than a tangible goal" might be in order.

The father is asked what Bobby would be like if he had more Syd in him. "Well, he would be a different kind of rider, that's for sure," answers Rob. "But the more interesting question is: What if Syd had been normal? What kind of competition would we have had between them? I have to think that wouldn't have gone well, and it's a small blessing they had parallel courses, not colliding ones."

So let's make this clear: As athletes, there is no comparison between Bobby and Syd. Bobby is an Olympian, Syd is a Special Olympian who could potentially become a good Category 3 rider—about the level at which amateur racers are considered decent. Bobby indulgently entertains the question of his training with Syd and answers that neither of them would get anything out of it. "As a purely physiological athlete, Syd is very gifted, and, had he not had a brain injury, he would undoubtedly be better than me in some areas," says Bobby. "But what holds Syd back is handling himself during a race. Track racing is about conservation of energy, learning when and where to fire your bullets and where to save your energy. Syd will never be able to master those things."

Bobby says Syd is luckier than him in one racing respect, though. "Syd gets very frustrated when he performs below expectations because he can't figure out why things didn't go right," says Bobby. "Maybe he forgot to eat before the race, or he had bad positioning in the bunch, or he was too far back before the sprint. He doesn't know that's the reason, and, in a way, being able to forget is a blessing. I'm still trying to wipe out memories from Beijing."

That's where Bobby and three teammates (Friedman, Sarah Hammer, and Jennie Reed) were involved in a brief but spectacular media and political uproar after photographers snapped them wearing antismog masks—as advised by USA Cycling, which subsequently passed the blame to the riders when the host country voiced disapproval. In part because he was unnerved by the worldwide whirlwind of controversy, Bobby finished well back in both the Madison and the points race. (Hammer, a world champion on the track who had been expected to win a medal, perhaps even a gold one, seemed to succumb to stress, too, finishing fifth in the pursuit and crashing in the points race.)

Still, there are times when it is Syd's world, and everyone else, including Bobby the Olympian, are just living in it. "On occasion," says Bobby, "people have said to me, 'Oh, you're Syd Lea's brother.'" The brothers are asked who is the more famous. Syd lets loose with a loud guffaw.

"I guess it depends on where you're at when you ask the question," says Bobby.

But, just as we can't ask Syd to be Bobby, it is unfair to ask Bobby to be Syd. The pressure is always greater on Bobby, who lives in a world of expectation, not just competition, and faces a future as not just a brother but as a brother's keeper.

THERE IS THE TENDENCY, when reflecting upon the Lea family, to deal in absolutes. You think what a shame it is that Syd is intellectually impaired. Then you see what he can do, how the family handles it. You see, for example, the clocks on the wall of Syd's bedroom, set to various international time zones, all of which he has visited. How many 26-year-olds of any intelligence level can tell you what time it is right now in Anchorage, Tehran, or Omsk, a city in southwestern Siberia where Syd went to train—alone—several years ago? You think about the miles traveled, the fascinating places seen, the friends gathered, the respect earned, and all those medals, ribbons, and inches of newspaper copy, and they are testaments to a life lived fully and well.

Just as it isn't all tragic, it isn't all wonderful, of course. Life has been, and will continue to be, messy and frustrating at times for the Leas, just as it is for all families. Sure, Dad is a psychologist who wrote his Harvard dissertation on "Acting-Up Disorders in Young Children," but that didn't give him a head start when Syd came home from the hospital. "What I know about intellectual disability," says Rob, "I know first-hand by living with it." It was trial-and-error for Tracy, too, even though she had experience working with troubled kids before Syd came along. When Bobby was a teenager they were arguing over one thing or another, and Tracy said to him: "Okay, Bobby, give me the manual. If there is one, I'll follow it. And if it's really a problem, take it up with your therapist later in life."

Syd has achieved much and gone far. But, still, he is mothered and fathered almost every day, and at this point in his life he'd be lost without it. He knows enough basic math to make conversions from two cups to six when he and Erin triple a Christmas-cookie recipe. He has the discipline to train his body for long bike races and enervating lactic-acid-producing rowing sprints. He has flown alone to more strange lands than many CEOs. Yet at other times, he treats hundred-dollar bills the same as ones, he tears through a supersized bag of chips in one sitting, and his mother worries every time he climbs into his VW Jetta. The point is, he traverses an unpredictable life course. And several months ago the parents decided to have what Tracy calls "The Conversation" with Bobby.

"You know, we won't always be here," they told their oldest, "and it's going to be up to you to take care of Syd." Tracy softened the blow a little by adding: "Bobby, you'll never have to mow the lawn, take out the trash, or shovel the snow."

Bobby was taken aback for a moment, but he wasn't all that surprised.

"They were re-doing their wills, and, though I hadn't thought about it much, part of me always assumed I'd take care of Syd," he says. "There was a time when we thought that if the planets aligned Syd might find the right girl and get married. But as he gets older it just doesn't seem to be in the cards. So...it's me."

So...it's Bobby, the young man who for so long has lived just outside the innermost circle of the cycling world, a shadow rider, a human being of so much potential who has not found his way to the top. It just might be that the explanation everyone is searching for lies in the fact that, however much he might have seemed born to be a bicycle racer, Bobby somehow comes into sharpest focus when aligned with his brother, a brother who is himself such a puzzle in many ways but so easy to grasp in others.